I consider lighting units the paint brushes of stage lighting. It is with these brushes that we can deliver the shape, texture, amount and color of light. Sometimes we need big brushes (strip lights) and sometimes we need tiny brushes (“lekos” and pin spots). If you have to paint a whole sky, you would need a really big brush. If you wanted to add a cloud, then you would use a smaller brush. If you wanted to add highlights and shadow lines to that cloud, you would even use even a smaller detail brush. A painter has many tools; so do you.
Theatrical manufacturers have gone to great lengths to give us lighting units and control systems that permit us to manipulate the elements of light. Every time a designer thinks, “Gee, I would love for it to do this,” there is an inventor out there to manufacture it. While it is not completely necessary for a lighting designer to understand all of the electrical and engineering components of how the systems work, it is vitally important that they understand what is available to them.